PLearn 0.1
MulticlassLossVariable.cc
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00001 // -*- C++ -*-
00002 
00003 // PLearn (A C++ Machine Learning Library)
00004 // Copyright (C) 1998 Pascal Vincent
00005 // Copyright (C) 1999-2002 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
00006 // Copyright (C) 2001-2002 Nicolas Chapados, Ichiro Takeuchi, Jean-Sebastien Senecal
00007 // Copyright (C) 2002 Xiangdong Wang, Christian Dorion
00008 
00009 // Redistribution and use in source and binary forms, with or without
00010 // modification, are permitted provided that the following conditions are met:
00011 // 
00012 //  1. Redistributions of source code must retain the above copyright
00013 //     notice, this list of conditions and the following disclaimer.
00014 // 
00015 //  2. Redistributions in binary form must reproduce the above copyright
00016 //     notice, this list of conditions and the following disclaimer in the
00017 //     documentation and/or other materials provided with the distribution.
00018 // 
00019 //  3. The name of the authors may not be used to endorse or promote
00020 //     products derived from this software without specific prior written
00021 //     permission.
00022 // 
00023 // THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
00024 // IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00025 // OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
00026 // NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00027 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
00028 // TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
00029 // PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
00030 // LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
00031 // NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
00032 // SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
00033 // 
00034 // This file is part of the PLearn library. For more information on the PLearn
00035 // library, go to the PLearn Web site at www.plearn.org
00036 
00037 
00038 /* *******************************************************      
00039  * $Id: MulticlassLossVariable.cc 6351 2006-10-25 19:05:45Z chapados $
00040  * This file is part of the PLearn library.
00041  ******************************************************* */
00042 
00043 #include "MulticlassLossVariable.h"
00044 
00045 namespace PLearn {
00046 using namespace std;
00047 
00048 
00051 PLEARN_IMPLEMENT_OBJECT(MulticlassLossVariable, 
00052                         "ONE LINE DESCR",
00053                         "NO HELP");
00054 
00055 MulticlassLossVariable::MulticlassLossVariable(Variable* netout, Variable* target)
00056     : inherited(netout,target,1,1)
00057 {
00058     build_();
00059 }
00060 
00061 void
00062 MulticlassLossVariable::build()
00063 {
00064     inherited::build();
00065     build_();
00066 }
00067 
00068 void
00069 MulticlassLossVariable::build_()
00070 {
00071     if (input1 && input2) {
00072         // input1 and input2 are (respectively) netout and target from constructor
00073         if(input1->size() != input2->size())
00074             PLERROR("In MulticlassLossVariable: netout and target must the same size");
00075     }
00076 }
00077 
00078 
00079 void MulticlassLossVariable::recomputeSize(int& l, int& w) const
00080 { l=1, w=1; }
00081 
00082 
00083 void MulticlassLossVariable::fprop()
00084 {
00085     real cost = 0.0;
00086     for (int i=0; i<input1->size(); i++)
00087     {
00088         real output = input1->valuedata[i];
00089         real target = input2->valuedata[i];
00090         PLASSERT( fast_exact_is_equal(target, 1) ||
00091                 fast_exact_is_equal(target, 0) );
00092         cost += fast_exact_is_equal(target, 1) ? output<0.5 : output>0.5;
00093     }
00094     valuedata[0] = cost;
00095 }
00096 
00097 
00098 
00099 } // end of namespace PLearn
00100 
00101 
00102 /*
00103   Local Variables:
00104   mode:c++
00105   c-basic-offset:4
00106   c-file-style:"stroustrup"
00107   c-file-offsets:((innamespace . 0)(inline-open . 0))
00108   indent-tabs-mode:nil
00109   fill-column:79
00110   End:
00111 */
00112 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=79 :
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